1. Field of the Invention
The present invention relates to the field of flat panel display technology, and more particular to an organic light emitting display (OLED) panel fabrication method and an OLED panel.
2. The Related Arts
Organic light-emitting display (OLED) possesses various advantages, such as being self-luminous, low drive voltage, high luminous efficiency, short response time, high clarity and contrast, nearly 180° view angle, wide range of operation temperature, and easy realization of flexible displaying and large-area full-color displaying, and is considered the most promising display device in the industry.
The OLED display technology is different from the traditional liquid crystal display technology in that no backlighting is necessary and a very thin layer of an organic material coating and a glass substrate are used instead, wherein when an electrical current flows through the organic materials, light emits therefrom. However, the organic material is susceptible to reaction with moisture and oxygen, as a display component based on organic materials, an OLED display screen requires a severe level of encapsulation. Encapsulating the OLED display device helps improve sealing of the interior thereof for isolation as much as possible from the outside. This is vital to stable light emission of the OLED device.
Heretofore, encapsulation of an OLED device is carried out by applying encapsulation gel on a rigid encapsulation substrate (made of glass or metal). Such a solution is not fit to flexible devices. Thus, techniques are available for encapsulation of an OLED device with stacked films. Such film-based encapsulation generally involves two layers of inorganic materials formed above an OLED device arranged on a substrate to form barrier layers having excellent property of resisting moisture and gas and a buffer layer made of an organic material that is flexible is arranged between the two barrier layers. Specifically, as shown in FIG. 1, a known film-encapsulated OLED device is provided, including a substrate 100, an OLED device 200 arranged on the substrate 100, and a film encapsulation layer 300 formed on the OLED device 200, wherein the film encapsulation layer 300 comprises a first inorganic barrier layer 310, an organic buffer layer 320 formed on the first inorganic barrier layer 310, and a second inorganic barrier layer 330 formed on the organic buffer layer 320.
The above film-based encapsulation is commonly used in encapsulating flexible OLED display screens. However, the encapsulation capability is generally difficult to achieve a level of which water vapor transmission rate (WVTR) is less than 10−6 g/m2/day and this often results in an issue of shortened life span of the flexible display screens.
In jet printing (IJP) technology has been recently used in encapsulation operations. An inkjet printer is a device that allows for localized coating to suit the design requirements and possesses the features of direct formation and reducing the need for metal masks and a vacuum environment, and an inkjet head of the printer generally include nozzles that have a diameter less than 100 μm, allowing for small and dense arrangements, and providing excellent capability of fine coating operations.